The dynamic assembly and disassembly of actin filaments is essential for the formation and transport of vesicles during endocytosis. In yeast, two types of actin structures, namely cortical patches and cytoplasmic cables, play a direct role in endocytosis, but how their interaction is regulated remains unclear. Here, we show that Srv2/CAP, an evolutionarily conserved actin regulator, is required for efficient endocytosis owing to its role in the formation of the actin patches that aid initial vesicle invagination and of the actin cables that these move along. Deletion of the SRV2 gene resulted in the appearance of aberrant fragmented actin cables that frequently moved past actin patches, the sites of endocytosis. We find that the C-terminal CARP domain of Srv2p is vitally important for the proper assembly of actin patches and cables; we also demonstrate that the N-terminal helical folded domain of Srv2 is required for its localization to actin patches, specifically to the ADP-actin rich region through an interaction with cofilin. These results demonstrate the in vivo roles of Srv2p in the regulation of the actin cytoskeleton during clathrin-mediated endocytosis

We are grateful to Anthony Bretscher (Cornell University, NY) for providing the bni1-12 bnr1Δ (Y4135) strain. J.Y.T. was supported by a Japan Society for the Promotion of Science (JSPS) KAKENHI grant [grant number 26440067]; the Takeda Science Foundation; and the Novartis Foundation (Japan). J.T. was supported by a JSPS KAKENHI grant [grant number 25440054]; the Takeda Science Foundation; and the Kurata Memorial Hitachi Science and Technology Foundation. D.E.S. was supported by the European Union [grant number PCIG12-GA-2012-334077].